U.S. patent number 4,827,550 [Application Number 07/191,859] was granted by the patent office on 1989-05-09 for removable head mechanism for automatic cleaning device.
This patent grant is currently assigned to Dental Research Corporation. Invention is credited to Cleve A. Graham, John Trenary.
United States Patent |
4,827,550 |
Graham , et al. |
May 9, 1989 |
Removable head mechanism for automatic cleaning device
Abstract
A cleaning apparatus is provided for transmitting powered motion
to an operating member having a removable head mechanism contained
within a hollow housing. A motorized base, including a base drive
shaft, is locked onto a head drive shaft of the removable head
mechanism in response to axial movement of the base drive shaft
into the housing. The head mechanism comprises a collet having
outwardly radiating arms and inwardly extending feet at the lower
end of the collet and a rack at the upper end. The rack engages
rotatable gears containing tufts of filaments. The base drive shaft
defines a shoulder and a tip at the upper end which is received
into the collet. A sleeve, retained within the head mechanism by
the inner dimensions of the hollow housing, receives the outwardly
radiating arms and compresses them over the tip of the base causing
the feet to engage the shoulder. Once locked onto the head
mechanism, the axial movement of the base drive shaft causes
rotation and counter-rotation of the gears and the tufts mounted
within the gears. Unlocking of the shafts is accomplished by
pulling the head mechanism away from the base. The rotational
movement of the tufts is useful for cleaning surfaces such as
teeth.
Inventors: |
Graham; Cleve A. (Simi Valley,
CA), Trenary; John (Lilburn, GA) |
Assignee: |
Dental Research Corporation
(Tucker, GA)
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Family
ID: |
27392961 |
Appl.
No.: |
07/191,859 |
Filed: |
May 4, 1988 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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891274 |
Jul 29, 1986 |
|
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743100 |
Jun 10, 1985 |
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Current U.S.
Class: |
15/22.1; 15/28;
403/326; 433/131 |
Current CPC
Class: |
A46B
3/06 (20130101); A46B 7/04 (20130101); A46B
9/04 (20130101); A46D 3/04 (20130101); A61C
17/34 (20130101); H02J 7/0045 (20130101); A46B
2200/1066 (20130101); Y10T 403/60 (20150115) |
Current International
Class: |
A46B
7/00 (20060101); A46B 3/00 (20060101); A46B
3/06 (20060101); A46B 7/04 (20060101); A46D
3/04 (20060101); A46B 9/04 (20060101); A46B
9/00 (20060101); A46D 3/00 (20060101); A61C
17/34 (20060101); A61C 17/16 (20060101); H02J
7/00 (20060101); A46B 013/02 () |
Field of
Search: |
;15/22R,22A,23,24,28,29,97R ;433/118,122,126,131 ;81/438,439,440
;51/17TL ;403/326,368,361,375 ;366/332 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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634607 |
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1114464 |
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2201745 |
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Oct 1972 |
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DE |
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2215799 |
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Oct 1972 |
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2363364 |
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Dec 1973 |
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DE |
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2263432 |
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May 1974 |
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DE |
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1632386 |
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Apr 1980 |
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DE |
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800826 |
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Jan 1936 |
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FR |
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934142 |
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Oct 1946 |
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FR |
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197806 |
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Oct 1976 |
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FR |
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2368854 |
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May 1978 |
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FR |
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480510 |
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May 1953 |
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IT |
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0033753 |
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Mar 1978 |
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JP |
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363635 |
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Mar 1959 |
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CH |
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190787 |
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Oct 1921 |
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GB |
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500517 |
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Feb 1939 |
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GB |
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1081021 |
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Aug 1967 |
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GB |
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Primary Examiner: Roberts; Edward L.
Attorney, Agent or Firm: Jones, Askew & Lunsford
Parent Case Text
This application is a continuation of Ser. No. 06/891,274, filed
July 29, 1986, now abandoned, which is a continuation-in-part of
Ser. No. 06/743,100, filed June 10, 1985, now abandoned.
Claims
We claim:
1. A removable head mechanism for use with a base having a base
drive shaft extending therefrom, comprising:
a hollow housing;
a head drive shaft slidably mounted for longitudinal movement
within said housing; and
means for connecting said base drive shaft to said head drive shaft
in locking relationship responsive to axial movement of said base
drive shaft into housing.
2. The removable head mechanism of claim 1, wherein said base
comprises:
means for driving said base drive shaft in a longitudinal
direction:
a bearing through which said base drive shaft passes; and
a seal through which said base drive shaft passes.
3. A removable head mechanism, for use with a base having a base
drive shaft extending therefrom, said base drive shaft defining a
shoulder spaced inwardly from the end of said shaft, said head
mechanism comprising:
a hollow housing;
a head drive shaft slidably mounted within said housing;
a flexible arm mounted for movement with said head drive shaft and
defining an inwardly extending foot at the end of said arm; and
locking means for selectively moving said arm between an unlock
position radially outwardly of the shoulder defined by said base
drive shaft and a lock position in which said foot engages said
shoulder when said head mechanism is mounted on said base.
4. The removable head mechanism of claim 3, further comprising
means for operating said locking means responsive to axial movement
of said base drive shaft into said housing.
5. The removable head mechanism of claim 4, wherein said locking
means comprises a hollow sleeve, operable to slidingly receive said
arm so as to cause said foot to engage said shoulder of said base
drive shaft.
6. The removable head mechanism of claim 5, wherein said housing
defines an interior ridge positioned in the path of said hollow
sleeve, said axial movement of said base drive shaft causing said
hollow sleeve to engage said ridge such that said arm slidably
enters said hollow sleeve.
7. The removable head mechanism of claim 6, further comprising
unlocking means for selectively moving said arm between a lock
position in which said foot engages said shoulder and an unlock
position radially outwardly of the shoulder defined by said base
drive shaft.
8. The removable head mechanism of claim 7, wherein said unlocking
means comprises a sleeve retainer defining an opening through which
said head drive shaft passes; said opening being smaller than the
external diameter of said sleeve; said sleeve retainer being
positioned so that, as said head mechanism is detached from said
base, said sleeve abuts said sleeve retainer and said sleeve is
slidably removed from said arm, releasing said foot from said
shoulder of said base drive shaft.
9. The removable head mechanism of claim 3, wherein said housing
defines a recess for receiving a work-engaging member operatively
connected to said head drive shaft, and further comprising:
a plate for covering said recess, said plate defining a bearing for
receiving said work-engaging member, and a tab extending across the
path of movement of said head drive shaft, said head drive shaft
being received for movement through an opening defined in said
tab.
10. The removable head mechanism of claim 9, further
comprising:
a shaft guide sleeve slidably receiving said head drive shaft and
defining a collar positioned to be matingly received within said
opening in said tab.
11. The removable head mechanism of claim 10, wherein said
work-engaging member comprises a rotatable tuft of filaments.
12. The removable head mechanism of claim 10, wherein said recess
includes a plurality of said work-engaging members, and wherein
said plate defines a plurality of said bearings;
said work-engaging members comprising a plurality of gears received
within said plurality of bearings in said plate, each of said gears
carrying a tuft of filaments; and
said head drive shaft defining a rack member operably connected to
said gears.
13. The removable head mechanism of claim 12, further comprising
means for connecting said rack member and said gears such that
reciprocation of said rack member causes said tufts to rotate in
one direction, and then causes said tufts to counter-rotate in an
opposite direction.
14. The removable head mechanism of claim 3, wherein said base
comprises:
means for driving said base drive shaft;
a bearing through which said base drive shaft passes; and
a seal through which said base drive shaft passes.
15. The removable head mechanism of claim 14, further comprising
means for operating said locking means responsive to axial movement
of said base drive shaft into said housing.
16. The removable head mechanism of claim 15, wherein said locking
means comprises a hollow sleeve, operable to slidingly receive said
arm so as to cause said foot to engage said shoulder of said base
drive shaft.
17. The removable head mechanism of claim 16, wherein said housing
defines an interior ridge positioned in the path of said hollow
sleeve, said axial movement of said base drive shaft causing said
hollow sleeve to engage said ridge such that said arm slidably
enters said hollow sleeve.
18. The removable head mechanism of claim 17, further comprising un
lock ing means for selectively moving said arm between a lock
position in which said foot engages said shoulder and an unlock
position radially outwardly of the shoulder defined by said base
drive shaft.
19. The removable head mechanism of claim 18, wherein said
unlocking means comprises a sleeve retainer defining an opening
through which said head drive shaft passes; said opening being
smaller than the external diameter of said sleeve; said sleeve
retainer being positioned so that, as said head mechanism is
detached from said base, said sleeve abuts said sleeve retainer and
said sleeve is slidably removed from said arm, releasing said foot
from said shoulder of said base drive shaft.
20. The removable head mechanism of claim 3, further comprising
unlocking means for selectively moving said arm between a lock
position in which said foot engages said shoulder and an unlock
position radially outwardly of the shoulder defined by said base
drive shaft.
21. An apparatus for transmitting powered motion to an operating
member, said apparatus comprising:
a base including a base drive shaft extending therefrom;
means mounted in said base for reciprocating said base drive shaft
axially;
a removable head mechanism including a head drive shaft slidably
mounted for axial movement within a hollow housing and operatively
associated with said operating member; and,
locking means for connecting said base drive shaft to said head
drive shaft actuated solely by axial movement of said base drive
shaft into said hollow housing of said head mechanism.
22. An apparatus for transmitting powered motion to an operating
member, said apparatus comprising:
a base including a base drive shaft extending therefrom, defining a
shoulder spaced inwardly from the end of said base drive shaft;
a removable head mechanism including a head drive shaft slidably
mounted within a hollow housing;
a flexible arm mounted for movement with said head drive shaft and
defining an inwardly extending foot at the end of said arm; and
locking means for selectively moving said arm between an unlock
position radially outwardly of the shoulder defined by said base
drive shaft and a lock position in which said foot engages said
shoulder when said head mechanism is mounted on said base.
23. The apparatus of claim 22, further comprising means for
operating said locking means responsive to axial movement of said
base drive shaft into said housing.
24. The apparatus of claim 23, wherein said locking means comprises
a hollow sleeve, operable to slidingly receive said arm so as to
cause said foot to engage said shoulder of said base drive
shaft.
25. The apparatus of claim 24, wherein said housing defines an
interior ridge positioned in the path of said hollow sleeve,
causing the retention of said hollow sleeve as axial movement of
said base drive shaft causes said head drive shaft to slidably
enter said hollow sleeve causing said foot to engage said shoulder
of said base drive shaft.
26. The apparatus of claim 25, comprising unlocking means for
selectively moving said arm between a lock position in which said
foot engages said shoulder and an unlock position radially
outwardly of the shoulder defined by said base drive shaft.
27. The apparatus of claim 26, wherein said unlocking means
comprises a sleeve retainer with an opening larger than said head
drive shaft; said opening being smaller than the external diameter
of said sleeve; said sleeve retainer being positioned so that, as
said head mechanism is detached from said base, said sleeve abuts
said sleeve retainer and said sleeve is slidably removed from said
arm, releasing said foot from said shoulder of said base drive
shaft.
28. An apparatus for transmitting powered motion to a work-engaging
member, said apparatus comprising:
a housing defining a recess therein;
a work-engaging member positioned within said recess;
a drive shaft;
means for operably connecting said drive shaft to said
work-engaging member;
a plate for covering said recess, said plate defining a bearing for
receiving said work-engaging member; and
a tab extending from said plate across the path of movement of said
drive shaft, said drive shaft being received for movement through
an opening defined in said tab.
29. The apparatus of claim 28, further comprising:
a shaft guide sleeve slidably receiving said drive shaft and
defining a collar positioned to be matingly received within said
opening in said tab.
30. The apparatus of claim 29, wherein said work-engaging member
comprises a rotatable tuft of filaments.
31. The apparatus of claim 30, wherein said recess includes a
plurality of said work-engaging members, and wherein said plate
defines a plurality of said bearings;
said work-engaging members comprising a plurality of gears received
within said plurality of bearings in said plate, each of said gears
carrying a tuft of filaments; and
said drive shaft defining a rack member operably connected to said
gears.
32. A method of connecting a base, having a base drive shaft
extending therefrom, to a removable head mechanism, comprising the
steps of:
axially inserting said base drive shaft into a hollow housing of
said head mechanism, said base drive shaft being adapted for axial
movement;
axially extending said base drive shaft to a predetermined extended
position; and
responsive solely to axial movement of said base drive shaft,
locking said base drive shaft to a head drive shaft slidably
mounted for axial movement within said housing of said head
mechanism.
33. The method of claim 32, wherein said base drive shaft is
axially extended to said predetermined extended position prior to
said step of axially inserting said base drive shaft into said
hollow housing.
34. A method of connecting a base, including a base drive shaft
extending therefrom, to a removable head mechanism, comprising the
steps of:
inserting said base drive shaft into a hollow housing of said head
mechanism, said base drive shaft defining a shoulder spaced
inwardly from the end of said shaft; and
responsive to axial movement of said base drive shaft, locking said
base drive shaft to a head drive shaft slidably mounted within said
housing, said head drive shaft including a flexible arm mounted for
movement with said head drive shaft, said flexible arm defining an
inwardly extending foot at the end of said. arm, so that said foot
of said flexible arm of said head drive shaft is inserted onto said
shoulder of said base drive shaft.
Description
TECHNICAL FIELD
The present invention relates to an apparatus for transmitting
powered motion to an operating member having a removable head
mechanism, and more particularly relates to an automatic cleaning
device such as a peridontal device having a removable toothbrush
attachment.
BACKGROUND OF THE INVENTION
Power tools have been available for many years for a variety of
different applications including cleaning or polishing. Automated
cleaning devices such as floor polishers, pot scrubbers, facial
massagers, fingernail polishers and electric toothbrushes utilize a
rapidly moving brush-like device at the end of a motorized drive
shaft. The drive shaft of these devices either spins continuously
in one direction or oscillates back and forth, and the brush device
moves with the drive shaft.
Originally, the brush members of such power tools were permanently
affixed to the drive shaft. Eventually, brush attachments were
devised so that, when the scrubbing surface of the attachment lost
its abrasive qualities, the attachment could be inexpensively
replaced instead of replacing the entire unit. However, these
attachments did not contain any independently moving parts, and the
brush movement was limited to the rotational or alternating
movement of the drive shaft.
U.S Pat. No. 4,156,620 discloses an apparatus for cleaning teeth
wherein the brush portion of the apparatus contains a number of
tufts which independently rotate and counter-rotate in response to
the axial movement of a single drive shaft. This unusual brush
movement has been shown to be successful in the prevention of
cavities and peridontal problems caused by bacterial plaque.
U.S. patent application Ser. No. 743,100 describes a related
cleansing apparatus which can be used for various cleaning
applications including use by the dental patient in the home as a
plaque-removing device. This apparatus is battery operated and sits
in a recharging base until used.
The automatic cleaning device of U.S. Pat. No. 4,156,620 and U.S.
patent application Ser. No. 743,100 is constructed as a one-piece
unit. Therefore, if different brushes or replacement brushes are
desired, the consumer will be forced to purchase an entire unit for
each new brush or replace the tufts one at a time; and, if the
device is used as a home plaque-removal instrument, separate units
will be required by each user in any particular household.
Providing the described automatic cleaning device as a two-piece
unit with a separate brush-containing head mechanism and a
power-driven base presents special problems. Unlike conventional
power tools, the brush portion of the above-described automatic
cleaning device contains moving parts. Therefore, a simple,
snap-on, brush-containing head member would be unable to translate
the movements of the power drive contained within the base to the
movable brushes contained within the head. Thus there is a need for
a connection that can securely attach the powered drive shaft
within the base to a reciprocating brush driving means within the
brush-containing head.
SUMMARY OF THE INVENTION
The present invention satisfies the need for a two-piece automatic
cleaning device with a removable head mechanism. The user can use
the same base assembly with any of a number of different head
mechanisms, so that the device can be used in a variety of
cleansing applications. In addition, by purchasing several
toothbrush head mechanisms, entire households can share the use of
a single plaque-removing device.
Generally described, the present invention provides a removable
head mechanism, for use with a base having a base drive shaft
extending therefrom, comprising a hollow housing, a head drive
shaft slidably mounted within the housing, and means for connecting
the base drive shaft to the head drive shaft in response to axial
movement of the base drive shaft into the housing. More
particularly described, the present invention provides a removable
head mechanism, for use with a base having a base drive shaft
extending therefrom, in which the base drive shaft defines a
shoulder spaced inwardly from the end of the shaft, and the
removable head mechanism comprises a hollow housing, a head drive
shaft slidably mounted within the housing, a flexible arm mounted
for movement with the head drive shaft with an inwardly extending
foot at the end of the arm, and locking means for selectively
moving the arm between an unlocked position radially outwardly of
the shoulder defined by the base drive shaft and a locked position
in which the foot engages the shoulder.
Preferably, the locking means comprises a hollow sleeve, large
enough to receive the head drive shaft and the flexible arm,
wherein the act of sliding the flexible arm into the sleeve causes
the foot to flex inwardly to engage the shoulder of the base drive
shaft. Also provided is means for removing the flexible arm from
the sleeve, causing the foot to be released from the shoulder.
Somewhat more particularly described, the housing of the head
mechanism defines an interior ridge or shoulder positioned in the
path of the hollow sleeve, causing the retention of the hollow
sleeve as axial movement of the base drive shaft causes the head
drive shaft to slidably enter the hollow sleeve, which in turn
causes the foot to engage the shoulder of the base drive shaft. The
removable head mechanism also includes unlocking means which
comprises a sleeve retainer ring with an opening larger than the
head drive shaft, but smaller than the external diameter of the
sleeve. The sleeve retainer is positioned so that, as the head
mechanism is detached from the base, the sleeve abuts the sleeve
retainer and the sleeve is slidably removed from the arm, releasing
the foot from the shoulder of the base drive shaft.
Preferably, the base of the present invention comprises a base
drive shaft, means for driving the base drive shaft, a bearing
through which the base drive shaft passes, and a seal through which
the base drive shaft passes.
The present invention also provides a recess for receiving a
work-engaging member operatively connected to the head drive shaft.
A plate covers the recess and defines a bearing for receiving the
work-engaging member, and a tab extends across the path of movement
of the head drive shaft with an opening in the tab through which
the head drive shaft passes.
It will thus be seen that the present invention provides an
apparatus for transmitting powered motion to an operating member,
comprising a base having a base drive shaft extending therefrom, a
removable head mechanism having a head drive shaft slidably mounted
within a hollow housing, and means for connecting the base drive
shaft to the head drive shaft responsive to axial movement of the
base drive shaft in the housing.
Thus, it is an object of the present invention to provide a
removable head mechanism for an automatic cleaning device.
It is a further object of the present invention to provide a head
mechanism with moving parts that can be driven by a head drive
shaft connected to a powered base drive shaft.
It is a further object of the present invention to provide a head
mechanism that can be quickly and easily attached and detached from
a base without the use of tools.
It is a further object of the present invention to provide an
apparatus with a head mechanism, containing moving parts, removably
attached to a power-driven base.
It is a further object of the present invention to provide a
power-driven base which can be removably attached to a variety of
head mechanisms.
It is a further object of the present invention to provide a
removable head mechanism capable of containing rotating tuft
filaments.
Other objects, features, and advantages of the present invention
will become apparent in the following detailed description of
preferred embodiments of the invention, when taken in conjunction
with the drawing and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial view of a cleaning apparatus embodying the
present invention.
FIG. 2 is a pictorial view of the base of the present invention
with the removable head mechanism removed.
FIG. 3 is an exploded perspective view of the removable head
mechanism and portions of the base of the cleaning apparatus shown
in FIG. 1.
FIG. 4 is a front vertical cross sectional view of the apparatus of
FIG. 1 with the base drive shaft in the extended position.
FIG. 5 is a front vertical cross sectional view of the apparatus of
FIG. 1 with the base drive shaft in the retracted position and
showing the gears which drive tufts of filaments.
FIG. 6 is a side vertical cross sectional view taken along line
6--6 of FIG. 4 with the base drive shaft in the extended
position.
FIG. 7 is a perspective view of the upper portion of the head
mechanism with portions broken away to show interior detail.
FIG. 8 is a perspective view of a second embodiment of the upper
portion of the head mechanism with portions broken away to show
interior detail.
FIG. 9 is a front vertical cross sectional view of the head
mechanism shown in FIG. 4 in the unlocked position, removed from
the base.
FIG. 10 is a side vertical cross sectional view of an alternate
embodiment of the middle portion of the head mechanism of the
invention, with the base drive shaft in the extended position.
FIG. 11 is a front vertical cross sectional view of an alternate
embodiment of a middle portion of the head mechanism of the
invention, with the base drive shaft in the retracted position.
DETAILED DESCRIPTION
Referring now in more detail to the drawing, in which like
reference numerals represent like parts throughout the several
views, FIG. 1 shows a cleaning device 10 embodying the present
invention. The preferred embodiment of the cleaning device includes
a base 12 removably attached to a head mechanism 14.
As best shown in FIG. 2, the base 12 comprises a hollow housing 13
which may be fabricated out of molded plastic or a similar
material. The base 12 is comprised of an upper portion 15 and a
lower portion 16. The upper and lower portions 15 and 16 are joined
together at 17 so that the resulting seal is waterproof. The foot
19 of the lower portion 16 of the base 12 is designed to fit within
a recharging device (not shown). A recharging apparatus suitable
for use in the base 12 is described in application Ser. No.
743,100, which is expressly incorporated herein by reference in its
entirety. A power switch 18 is connected to the motorized driving
means of the device, shown in FIG. 6, and lies adjacent to the
external housing of the upper portion 15 of the base 12 in a
position where it can be easily manipulated by the thumb of a hand
grasping the cleaning device 10.
In the preferred embodiment of the present invention, a hollow neck
20 extends upwardly from the upper portion 15 of the housing 13 of
the base 12. The neck 20 defines a flat, D-shaped top surface 22
including a mouth 23 opening into the interior of the neck, and a
flat front surface 24. A round headed screw 25, preferably
metallic, is driven into the flat front surface 24 to aid in
securing the removable head mechanism 14 to the base 12. In an
alternative embodiment (not shown) the neck 20 of the base 12 is
cylindrical with a chamfer or beveled edge upon which the removable
head is secured only by friction.
A base drive shaft 30, having an outermost end 32, extends through
the mouth 23 of the neck 20 of the base 12 and includes an annular
indented region 34 spaced a short distance from the end 32 of the
shaft 30, creating a tip 36 and a shoulder 38 facing the upper
portion 15 of the base housing 13. The tip 36 is tapered at the end
32 to facilitate insertion into the head mechanism 14.
As shown in FIGS. 3, 4, 5, and 6, the base drive shaft 30 extends
downwardly into the neck 20 where it passes through a seal 40 which
has a cylindrical collar 42 closely fitting between the mouth 23
and the shaft 30. The seal 40 prevents fluids or dust from entering
the housing 13 while permitting movement of the shaft 30 with
respect to the housing 13. In the embodiment shown, such movement
is reciprocation out of and into the housing. Below the seal 40, a
cylindrical bearing 50 is secured within the neck 20. The bearing
50 receives the shaft 30 for sliding movement within the bearing.
Below the bearing 50 a shaft retaining bracket 60 is positioned in
the housing 13. The bracket 60 defines at its upper end a
cylindrical collar 62 shaped to be matingly received within the
neck 20, where the collar 62 assists in retaining the bearing 50
within the neck. The penetration of the collar 62 into the neck 20
is limited by a flange 64 extending outwardly beyond the collar. A
lower bearing member 66 is held in spaced apart relation to the
flange 64 by a slotted tube 68. A pair of wings 65 and 67 adjacent
to the slotted tube 68 aid in positioning the slotted tube in the
center of the housing 13. The drive shaft 30 passes freely through
the collar 62 and flange 64 and is slidably received by the lower
bearing 66. Thus, the path of the drive shaft 30 is defined by the
bearings 50 and 66.
A motor 70 and transmission gears 80 and 85, shown in FIG. 6, of
the type shown in application Ser. No. 743,100, are mounted within
the base housing 13 below the rear bearing member 66, and are
drivingly connected to the drive shaft 30. The motor 70 is
essentially cylindrical, having a circular or D-shaped top plate 72
with a central bore 74. A vertical support member 75 extends
vertically at right angles from the top plate 72 of the motor 70. A
gear drive shaft 76 extends from the motor through the bore 74. The
external diameter of the top plate 72 is equal to the internal
diameter of the base housing 16 and is press fit into a groove 78
in the base housing 16. The motor 70 is thus suspended within the
base housing 16 from the attached top plate 72.
A pinion gear 80 is mounted at the uppermost portion of the gear
drive shaft 76 and meshes with a crown or face gear 85. The face
gear 85 is rotatably mounted on a horizontal shaft 87 which passes
through a central bore 86 in the vertical support member 75. When
the motor 70 is turned on by operation of the switch 18, rotation
of the pinion gear 80 causes rotation of the face gear 85 about a
horizontal axis perpendicular to the longitudinal axis of the base
housing 13.
A crank arm 90 connects the face gear 85 to the base drive shaft
30. A lower end 92 of the crank arm 90 is pivotally attached
eccentrically to the face gear at a lower pivot joint 94. An upper
end 96 of the crank arm 90 is pivotally connected to the base drive
shaft 30 at an upper pivot joint 98 located between the flange 64
and the rear bearing 66. When the motor is turned on, the rotation
of the face gear 85 causes the lower end 92 of the crank arm 90 to
move in a circular path defined by the movement of the face gear.
The connection at the upper pivot joint 98 and the restrictions of
the cylindrical bearing 50 and rear bearing 66 translate the
circular movement of the crank arm 90 into reciprocating axial
movement of the base drive shaft 30 described in more detail
below.
As shown best in FIGS. 3 and 9, the removable head mechanism 14
comprises a hollow housing 100 having an interior cavity 102 molded
in particular shapes creating connected chambers 104, 106, 108,
110, and 120 which accommodate the various pieces that make up the
head mechanism. A base-receiving chamber 104 is the same "D" shape
in cross section as the neck 20 of the base 12 and is designed to
fit snugly over the neck 20 of the base creating a friction fit
connection. In the preferred embodiment of the present invention,
as a further aid in connecting the head housing 100 to the base 12,
the round headed screw 25 is slidably received into an elongate
slot 103 formed through the wall of the head housing, shown best in
FIGS. 1 and 3. A circular opening 105, shown in FIGS. 3 and 6, is
formed intermediate the ends of the slot 103, such that the slot
103 allows the housing 100 to spread and receive the screw head 25
until the screw head becomes seated in the opening 105.
Returning to FIG. 9, immediately adjacent to the base-receiving
chamber 104 is a cylindrical collet chamber 106 having a slightly
smaller diameter than the interior dimension of the chamber 104.
Adjacent to the collet chamber is a cylindrical sleeve chamber 108
having a smaller diameter than the collet chamber 106, followed by
a cylindrical rack chamber 110 having the smallest diameter of the
chambers. A shoulder or ridge 109 is formed where sleeve chamber
108 meets rack chamber 110. The rack chamber 110 opens into gear
chamber or recess 120 which is of a size and shape large enough to
contain a number of rotatable circular gears 130 and 140. Circular
gears 130 are the driven gears whereas gears 140 are the drive
gears as will be explained in greater detail below.
As best shown in FIGS. 5, 6, 7, and 9, the gear chamber 120 defines
a floor 121 from which protrude a pair of bearing platforms 122
separated by an elongate channel 124. An opening in the lower
endwall 131 of the gear chamber 120 defines an entrance 125. The
bearing platforms begin at a point spaced apart from the entrance
125 to the gear chamber 120 from the rack chamber 110. At the
entrance 125 to the gear chamber, a groove 126 is formed in the
floor 121 of the gear chamber 120. The groove 126 continues along
the floor 121 within the elongate channel 124. Prior to the
entrance 125, the rack chamber 110 narrows to form a throat 112 for
a purpose described below.
Each of the bearing platforms 122 defines a plurality of staggered
cylindrical bores 132, shown best in FIG. 4, for receiving the
driven gears 130. When inserted into the bores 132, adjacent gears
130 mesh with one another in driving engagement. The floor 121
between the bearing platforms and the entrance 125, on opposite
sides of the groove 126, defines a pair of cylindrical bores 142
for receiving the gears 140.
At the upper end of the head mechanism 14, a slot 127 is cut out of
the wall of the gear chamber 120, as shown in FIGS. 4, 5, 6, and 9.
Below the slot 127, a notch 128, shown only in FIG. 6, is formed in
the outer wall of the head mechanism housing 100. The slot 127 and
notch 128 receive elements of a gear chamber cover 150, as
described below.
In an alternative embodiment of the present invention shown in FIG.
8, a notch 128a is formed in the inner wall of the upper end of the
head mechanism housing 100. This notch 128a receives elements of a
gear chamber cover 150a, as described below.
As shown best in FIG. 3, each circular gear 130 has an axis of
rotation perpendicular to the floor 121 of the gear chamber 120,
and has a lower shaft 134 which fits into one of the cylindrical
bores 132 formed in the bearing platforms 122. As each gear
rotates, the cylindrical bore 132 provides a bearing for the lower
shaft 134 of the gear 130. Each gear also has an upper collar 136
extending from the opposite surface of the gear, which holds a tuft
of filaments 138, shown in FIG. 6, of the type shown in application
Ser. No. 743,100. It will be understood that the tufts 138 comprise
work-engaging members and could be replaced by buffing, polishing,
grinding or other tools.
Each circular driving gear 140 also has an axis of rotation
perpendicular to the floor 121 of the gear chamber 120, and has a
lower shaft which fits into the cylindrical bores 142 formed in the
floor 121. As each gear rotates, the cylindrical bore 142 provides
a bearing for the lower shaft of the gear 140. Each gear also has
an upper collar 146 extending from the opposite surface of the
gear, which holds a tuft of filaments 148. The height of the gears
140 is sufficient so that the teeth of each gear extend from
approximately the level of the floor 121 to a height sufficient to
mesh with one of the gears 130 mounted on one of the bearing
platforms 122. As will be described below, only the gears 140
engage the driving apparatus within the chambers of the head
mechanism 14.
A gear chamber cover 150, shown in FIGS. 3, 6, and 7, provides a
removable cover for the gear chamber 120 and maintains the gears
130 and 140 within the chamber 120. The cover 150 includes a brush
plate 152, which defines a plurality of cylindrical openings 154
formed through the plate 152 aligned with the gear collars 136 and
146 of the gears 130 and 140. When the plate 152 is placed in
position covering the chamber 120, the gear collars are rotatably
received within the openings 154 which provide bearings for the
collars 136 and 146. The tufts 138 and 148 extend through the
openings 154 and protrude outwardly for engaging a surface to be
cleaned, such as a person's teeth.
At the lower end of the brush plate 152, a lower tab 156 extends at
right angles from the brush plate into a slot 155 defined by the
lower endwall 131 of the gear chamber 120 and the throat 112. The
tab 156 defines an opening 157 aligned with the entrance 125 to the
gear chamber 120 and the throat 112 of rack chamber 110. At the
upper end of the brush plate 152, an upper tab 158 extends at right
angles from the brush plate to fill the slot 127. A locking member
159 extends from the end of the tab 158 to engage the notch 128 and
retain the upper end of the cover 150 in position over the gear
chamber 120. Preferably, the cover 150 is formed of a flexible
material, such as a resilient plastic, so that the locking member
159 can be snapped into and out of the notch 128.
In the alternative embodiment shown in FIG. 8, two identical posts
158a, one of which is shown, extend downwardly at right angles from
the upper end of the brush plate 152a. A locking member 159a
extends from the end of each post to engage the notch 128a formed
in the interior wall. A tab 156a extends at right angles from the
lower end of the brush plate 152a. A locking member 161a extends
from the tab 156a and engages the throat 112a of the rack chamber
110a when the gear chamber cover 150a is positioned over the gear
chamber 120a.
In the preferred embodiment of the present invention, a cylindrical
rack guide 160 having a cross-shaped central bore 162 passing
through a body portion 164 and a collar 166 can be inserted into
the interior cavity 102 of the head mechanism 14. The collar 166
extends upwardly from the body 164 so that the collar 166 fits
tightly into the throat 112 of the rack chamber 110 and extends
into the entrance 125 to the gear chamber 120 and matingly through
the opening 157 of the lower tab 156, thus further securing the
cover 150 to the gear chamber 120. As shown in FIG. 8 and described
below, an alternative embodiment of the present invention does not
utilize the rack guide 160. Rather, the locking members 159a and
161a, described above, secure the gear chamber cover 150a in
place.
Referring further to FIGS. 3 and 9, a head drive shaft 170,
slidably mounted within the sleeve chamber 108 and the rack chamber
110, is provided for operating the gears 140. The head drive shaft
170 comprises an elongate rack 172 at the uppermost end 173 of the
rack 172. The rack 172 is cross-shaped in cross section, defining
four elongate ribs 174, 175, 176, and 177, oriented at right angles
to one another. Beginning at the end 173 of the rack, left and
right ribs 174 and 176 form rack teeth 178 extending along the
drive shaft 170. The shape of the entire rack 172 corresponds to
the cross shape of the rack guide 160 allowing slidable entry of
the rack 172 into the gear chamber 120 through the rack guide 160.
The rack guide 160 therefore assures that the rack 172 enters the
gear chamber 120 in the correct orientation so that the rack 172
properly engages the gears 140. The gears 140 are spaced apart
within the gear chamber 120 by a distance such that as the rack 172
enters the gear chamber 120, the rack teeth 178 of the ribs 174 and
176 operatively engage both of the gears 140 adjacent to the floor
121. Thus, axial movement of the head drive shaft 170 and rack 172
causes the drive gears 140 to rotate, and such rotation in turn
rotates the driven gears 130.
In the alternative embodiment shown in FIG. 8, a grooved bar 163a
extends downwardly from the lower surface of the brush plate 152a.
A groove 165a in the bar 163a engages the upper rib 175 of the rack
172 when the brush plate is secured over the gear chamber 120a much
in the same manner as the rack guide 160. There is thus no need for
a rack guide in the alternative embodiment.
It will be understood by those skilled in the art that the rack 170
may be cylindrically shaped with rack teeth 178 continuously around
the entire perimeter of the rack.
At the lowermost end of the rack 172 of the preferred embodiment, a
notched portion 179, shown best in FIG. 9, is molded into a
cylindrical body portion 182 of a collet 180. The collet is
preferably molded from flexible plastic or the like so that it can
assume either a locked or an unlocked position as described below.
Four flexible arms 184 extend downwardly from the body portion 182
and radiate outwardly in the unlocked position. The arms terminate
in inwardly extending feet 186, which lie outside the radial
position of the cylindrical surface of the body portion 182 when
the collet is in the unlocked position.
A sleeve 190 comprises a hollow cylinder slidably received around
the body portion 182 of the collet 180. The external diameter of
the sleeve is small enough to slide freely within the sleeve
chamber 108, but is too large to pass the shoulder 109 into rack
chamber 110. In the unlocked position, the sleeve 190 surrounds the
collet at its cylindrical body portion 182. When the head mechanism
14 is locked onto the base 12, the sleeve 190 surrounds and
compresses the flexible arms 184 of the collet 180 as shown in
FIGS. 4 and 5.
A sleeve retainer ring 192 is press fit into the housing 100 at the
upper end of the collet chamber 106. As shown in FIGS. 3 and 9, the
sleeve retainer 192 of the preferred embodiment of the present
invention is circular in shape with a central bore 194 through
which the head drive shaft 170 and the body portion 182 of the
collet 180 can pass. The diameter of the sleeve retainer 192 is
such that it is too large to enter the sleeve chamber 108, but
small enough to be frictionally retained horizontally within the
collet chamber 106, adjacent to the sleeve chamber 108. It will be
seen from FIG. 9 that the sleeve 190 and sleeve retainer 192 can be
placed over the drive shaft 170 before the shaft 170 is inserted
into the cavity 102. The retainer ring 192 can then be press fit
into the wall of the cavity as shown while surrounding the head
drive shaft 170 or the collet 180. Alternately, the sleeve 190 can
be inserted into the sleeve chamber 108, the retainer ring 192
press fit into place, and the shaft 170 inserted through the
retainer ring and then through the sleeve.
After the insertion of the head drive shaft 170, a collet retainer
ring 200 is press fit into an annular notch 202 in the wall of the
cavity 102 between the base receiving chamber 104 and the collet
chamber 106. The collet retainer 200 comprises a dome shaped member
204 having an annular brim 206 extending outwardly from the dome
shaped member 204. A central bore 208 is formed in the center of
the dome shaped member, which preferably extends upwardly into the
collet chamber 106 as the brim 206 is press-fit into the annular
notch 202. In the unlocked position of the collet as shown in FIG.
9, the flexible arms 184 lie on the exterior of the dome 204 of the
collet retainer ring 200. It will be understood that the collet
retainer ring could be formed in alternate shapes so long as the
collet is prevented from falling out of the housing 100 and the
base drive shaft 30 can freely pass into the collet chamber 206. In
the preferred embodiment shown, the sloped surface of the dome
shaped member 204 can assist in removing the feet 186 from the
shoulder 38 of the base drive shaft 30 if there is any tendency of
the feet to adhere to the shoulder 38 after the sleeve has been
slidably removed from the arms 184 of the collet 180, as described
below.
In an alternative embodiment, shown in FIGS. 10 and 11, a modified
construction of a collet retainer ring 200a is shown. A tab 201a
extends upwardly at right angles from the rear portion of the brim
206a of the collet retainer ring 200a. A locking member 203a
extends outwardly from the upper end of the tab to engage an
indentation 207a which may be formed in the rear wall of collet
chamber 106. In addition, a pair of posts 205a extend upwardly at
right angles from the brim 206a and dome shaped member 204a on
either side of the central bore as shown best in FIG. 11. The posts
205a aid in removing the sleeve 190 from the flexible arms 184 of
the collet 180 when the removable head mechanism 14 is disengaged
from the base 12. When used, the retainer ring 200a replaces the
collet retainer ring 200, and the sleeve retainer ring 192 of the
previous embodiment.
Operation
The removable head mechanism 14 is engaged and disengaged with the
base 12 by the following procedure. Although the base drive shaft
30 may extend an indefinite distance from the neck 20 when the
power switch 18 is operated to turn off power to the motor 70, its
position is not critical to engaging or disengaging the removable
head mechanism 14. To engage the head mechanism with the base, the
head mechanism is grasped and moved downwardly toward the base so
that the neck 20 begins to enter the base receiving chamber 104.
The slot 103 moves over the round headed screw 25 until the screw
25 seats within the circular opening 105. The head mechanism 14 is
firmly attached to the base 12 when the flat upper surface 22 of
the neck 20 of the base comes in contact with the flat lower
surface of the collet retaining ring 200.
The base drive shaft 30 is inserted through the collet retainer
ring 200 into the collet chamber 106. The tip 36 of the base drive
shaft 30 is received between the outwardly radiating flexible arms
184 of the collet 180 as the neck 20 of the base is brought into a
mating relationship with the base receiving chamber 104 of the head
mechanism 14. If the base drive shaft is sufficiently extended, for
example as shown in FIG. 4, the action of inserting the base drive
shaft will move the head drive shaft upwardly within the sleeve
chamber 108 until the sleeve 190, carried by the body portion 182
of the collet 180, engages the shoulder 109 formed between the
sleeve chamber 108 and the rack chamber 110. Further insertion
pushes the sleeve over the arms 184 of the collet, causing the feet
186 to move inwardly into engagement with the shoulder 38 of the
base drive shaft 30. If, on the other hand, the base drive shaft 30
is initially in a lower position, such as shown in FIG. 5,
insertion of the neck 20 into the base receiving chamber 104 will
not fully engage and lock the head mechanism 14 to the base 12.
However, when the power switch 18 of the base 12 is engaged to
operate the motor 70, the base drive shaft 30 moves axially to the
extended position shown in FIG. 4. The sleeve 190 is carried with
the collet 180 of the head drive shaft 170 until it abuts the
shoulder 109 at the uppermost portion of the sleeve chamber 108.
The sleeve 190 is then held stationary as the base drive shaft
pushes the collet 180 of the head drive shaft further into the rack
chamber 110. The flexible arms 184 of the collet 180 flex inwardly
as they enter the sleeve 190 and each foot 186 moves into the
annular indented region 34 of the base drive shaft at the shoulder
38 in a locked position as shown in FIGS. 4 and 6.
Regardless of whether locking occurs during manual assembly of the
head mechanism onto base or when the power is turned on, as the
drive shaft moves upwardly during the locking procedure, the rack
172 slides through the rack guide 160 and enters the gear chamber
120. The rack teeth 178 engage the gears 140 and the rack 172
slides along the channel 124 toward the slot 127.
Once the head mechanism has been locked onto the base, the head
drive shaft 170 reciprocates the axial movements of the base drive
shaft 30. During such movement, the sleeve 190 remains in place
compressing the arms 184 of the collet 180. The tip 36 of the base
drive shaft 30 remains entrapped by the arms 184 and the feet 186
and moves with the head drive shaft 170 from an uppermost position
shown in FIG. 4 to a lowermost position shown in FIG. 5, according
to reciprocation of the crank arm 90. The rack 172 reciprocates
along the channel 124, causing the gears 140 to alternately rotate
and counter-rotate. This in turn causes a similar sequence of
rotation of the gears 130. Thus, the tufts of filaments 138 and 148
are caused to rotate as described in application Ser. No. 743,100,
creating a cleaning action particularly useful in removing dental
plaque.
To disengage the head mechanism 14 from the base 12, the head
mechanism is grasped and moved upwardly away from the base so that
the base receiving chamber 104 is lifted from the neck 20. As the
head mechanism is thus moved, the round headed screw 25 is
dislodged from the circular opening 105 and is moved along the slot
103 until released from the head housing 100.
The base drive shaft 30 is unlocked from the collet 180 of the head
drive shaft 170 by the release of the arms 184 from the sleeve 190.
If the base drive shaft 30 is sufficiently retracted, for example
as shown in FIG. 5, the sleeve 190 is positioned adjacent to the
sleeve retainer ring 192. Upward movement of the head mechanism
causes the withdrawal of the base drive shaft 30, surrounded by the
arms 184 of the collet 180, from the sleeve 190. If the base drive
shaft is not sufficiently retracted, the upward movement of the
head mechanism 14 causes the sleeve to freely slide downwardly
within the sleeve chamber 108 until it engages the sleeve retainer
ring 192. Further upward movement of the head mechanism causes the
withdrawal of the base drive shaft 30, surrounded by the arms 184
of the collet 180, from the sleeve 190. The sleeve is retained by
the sleeve retaining ring 192 as the base drive shaft 30 and
attached collet 180 descend through the central bore 194 of the
sleeve retaining ring 192. The withdrawal action causes the
flexible arms 184 to regain their outwardly radiating unlocked
position, shown in FIG. 9.
In the alternate embodiment shown in FIGS. 10 and 11, the posts
205a engage the sleeve 190 as upward movement of the head mechanism
causes the withdrawal of the base drive shaft 30, surrounded by the
arms 184 of the collet 180, from the sleeve 190. The posts 205a
perform the same function as the sleeve retaining ring 192 found in
the first embodiment and thus replace the sleeve retaining ring.
FIG. 11 shows the sleeve 190 about to engage the posts 205a.
In the preferred embodiments shown, the sloped surface of the dome
shaped members 204 and 204a of the collet retainer rings 200 and
200a aids in the removal of the feet 186 from the shoulder 38 of
the base drive shaft 30. As the flexible arms 184 are withdrawn
from the sleeve 190, the gradually increasing external diameter of
the domed shaped members 204 and 204a provides a wedge-like
function, prying the feet 186 from the shoulder 38 if there is any
tendency for the feet to adhere to the shoulder.
Further upward movement of the head mechanism 14 causes the base
drive shaft 30 to descend through the central bore 208 of the
collet retainer ring 200. However, the outwardly radiating flexible
arms 184 of the collet cannot pass through the central bore 208 of
the collet retainer ring, preventing the downward passage of the
head drive shaft 170 through the central bore 208. The collet is
thus retained within the collet chamber 106, the sleeve is retained
within the sleeve chamber 108, and the rack 172 remains partially
within the sleeve chamber and partially within the rack chamber 110
as shown in FIG. 9, so that a portion of the rack remains within
the rack guide 160.
Once the base drive shaft 30 has been unlocked from the collet 180
of the head drive shaft 170, further upward movement of the head
creates a total separation of the base 12 from the head mechanism
14.
Thus, it will be seen that the present invention provides a
removable head mechanism with its own axial drive shaft and a novel
means for automatically connecting and disconnecting the head drive
shaft to the power driven shaft of a base which serves as a handle
for manipulating the tool as a whole.
While this invention has been described with particular reference
to preferred embodiments thereof, it will be understood that
variations and modifications can be made without departing from the
spirit and scope of the invention as described hereinbefore and as
defined in the appended claims.
* * * * *